We traditionally use GCS to triage patients who sustained traumatic brain injury. Some previous studies have reported how the accuracy of using GCS decreases with increasing age. Specifically, the elderly present with a higher GCS than younger patients when suffering the same injury. A large study presented in EMJ confirms those findings.
This is another massive database study coming out of the TARN project. It includes 25.082 patients, comparing ‘old patients’ (n=10.936, mean age 81 years) and ‘young patients’ (n=14.146, mean age 37 years) in regards to the presenting GCS after isolated traumatic brain injury. GCS was plotted against AIS severity score as well as mechanism of injury and type of injury. The AIS is a coding system describing the location and anatomical severity of injuries.
The study confirmed the findings of previous studies in that presenting GCS was higher in elderly patients than in the young patient group when suffering the same severity of TBI. Interestingly, the difference increase with increased severity score. In the AIS grade 5 (critical injury) group the mean GCS was 9 in the young group versus 14 in the elderly.
Two previous smaller studies have reported the same phenomenon. That time the difference was suggested to be due to different mechanisms or types of injury. Therefore, the EMJ study further sub-grouped the patients. Again the presenting GCS was higher in the elderly patients regardless of the mechanism or type of injury.
To achieve the same reduction in GCS as younger patients, more severe injury is required in the elderly. This will inevitably result in under-triaging brain injury in older patients and will obviously result in delayed surgery and poor outcomes. At least as long as we use GCS or levels of consciousness as a triaging tool.
We probably knew this, but for me this paper is another nail in the coffin for the GCS as a clinical decision and triage tool.
For more on this, watch Mark Wilsons excellent take-down of the GCS (at least in the way we use it) at SMACC. It’s here.
The paper lives here (open access):
Older patients with traumatic brain injury present with a higher GCS score than younger patients for a given severity of injury. Kehoe A, Smith JE, Bouamra O, Edwards A, Yates D, Lecky F. Emerg Med J. 2016 Jun;33(6):381-5.